ITU-T formulates a new flexible optical transport data unit (ODUflex) frame. An ODUflex still keeps a frame structure of an original optical channel data unit-k (ODUk) and is capable of bearing a constant bit rate (CBR) service and a packet service at any rate. In the technical solutions of the prior art, a packet service is mapped to an ODUflex by using the Generic Framing Procedure-Frame-Mapped (GFP-F), and then the ODUflex is mapped to a higher order optical channel data unit (HO ODU) by using the Generic Mapping Procedure (GMP) and is transported by using a higher order optical channel transport unit (HO OTU). The ODUflex is mapped to several timeslots (TS) in the HO ODU by using the GMP. At a receive end and a transmit end of an optical transport network (OTN), a processing process of the ODUflex is as follows: At the receive end, an HO ODUk multiframe is demapped, by using a GMP mapping method according to the number (C′m) of m-bit client entities at the receive end, as an ODUflex bit stream that is then written in a first in first out queue (FIFO); and at the transmit end, an ODUflex bit stream output from the FIFO is mapped to an HO ODUj multiframe by using the GMP mapping method according to the number (Cm) of m-bit client entities at the transmit end. The receive end and the transmit end adjust Cm and C′m according to a rate change of the ODUflex, so that rates of the receive end and the transmit end is consistent with a rate of the ODUflex. The characteristics of the foregoing method are as follows: A phase difference exists between a header of the HO ODUk multiframe and a header of the HO ODUj multiframe, and a FIFO delay exists at the receive end and the transmit end, causing a propagation delay when a rate of the ODUflex bit stream changes.
Because flows of a packet service have a non-real-time change characteristic, different bandwidth needs to be provided for an ODUflex to meet its different flows, and ODUflex channel bandwidth needs to be adjusted under the circumstances that the packet service is not interrupted. When the flows of the packet service change, the transmit end and the receive end implement a hitless adjustment to the ODUflex channel bandwidth by using Cm and C′m, and a phenomenon that FIFO depth changes sharply occurs, so that a FIFO of large space is required, so as to avoid appearing of two states of the FIFO: empty and full. However, the space of the FIFO is limited. To solve the foregoing technical problems, a source NE uses a method for making Cm keep in a lower change rate and a smaller step, to keep a change rate of a rate of an ODUflex bit stream lower than 1 byte/100 us, so that the FIFO in 100 us automatically absorbs a jitter caused by a bit stream change.
However, in an existing process of adjusting ODUflex channel bandwidth, the change rate of Cm is lower and the step is smaller, leading to a longer period used to adjust the ODUflex channel bandwidth. When the flow of a packet service born by an ODUflex changes, requirements of dynamic network planning cannot be met.